A control device for an injection molding machine including a cylinder into which a resin is supplied and a screw that moves forward and rearward and rotates inside the cylinder, includes a metering control unit that performs metering of the resin inside the cylinder by controlling forward rotation and rearward movement of the screw until the screw has been moved rearward to a predetermined metering position, based on predetermined metering conditions, a rearward movement speed acquisition unit acquiring a rearward movement speed of the screw, a speed determination unit that determines a suck back speed for causing a resin pressure to reach a target pressure, based on the rearward movement speed acquired during metering by the rearward movement speed acquisition unit, and a suck back control unit causing the screw to move further rearward based on the suck back speed, after the screw has reached the predetermined metering position.

A control device for an injection molding machine is equipped with a pressure acquisition unit that acquires a pressure of a resin, a reverse rotation control unit that causes a screw to be rotated in reverse, after the screw has reached a predetermined metering position, a measurement unit that measures an elapsed time or a rotation amount of the screw from when the screw has reached the predetermined metering position, and a rearward movement control unit that initiates sucking back of the screw in an overlapping manner with the reverse rotation of the screw, in the case that a predetermined rearward movement initiation time has elapsed, or in the case that the screw has been rotated by a predetermined rearward movement initiation rotation amount, from when the screw has reached the predetermined metering position.

An injection molding machine includes: a target pressure acquisition part that acquires a target pressure at which a flow rate of a molten resin discharged through a discharge nozzle meets a specified flow rate; an estimated outflow amount calculation part that calculates an estimated outflow amount that is an estimated value of the molten resin discharged through the discharge nozzle per unit time; and a moving speed calculation part that calculates a specified moving speed that is a sum of a moving speed of a piston at which a pressure applied to the molten resin inside a cylinder meets the target pressure and a moving speed of the piston at which the flow rate of the molten resin discharged through the discharge nozzle per unit time meets the estimated outflow amount.

Provided is an injection molding method for resin that contains reinforcing fiber, the method being capable of easily eliminating uneven distribution of added components. The injection molding method is provided with: a plasticizing step for supplying resin pellets P and added components to a cylinder equipped with a screw 10, which has a rotating axis as the center is capable of rotating normally and in reverse, and generating molten resin by rotating the screw 10 in the normal direction; and an injecting step for injecting the molten resin M comprising the added components into a cavity. In the plasticizing step, a reverse rotation operation for reversing the rotation of the screw 10 is performed or a screw-stopping operation of stopping the normal rotation of the screw 10 is performed with a prescribed timing and for a prescribed period.

A plasticizing device includes a plasticizing mechanism including a feeding port for receiving a material and configured to plasticize the material to generate a melted material and a material feeding mechanism configured to feed the material to the plasticizing mechanism. The material feeding mechanism includes a housing including a depositing port communicating with the feeding port, the housing storing the material, and a rotating member housed in the housing and capable of rotating along an inner edge of the housing. A plurality of through-holes are provided in the rotating member at intervals along an outer circumference of the rotating member. When the rotating member rotates and any one of the plurality of through-holes and the depositing port communicate, the material stored in the housing is fed from the feeding port to the plasticizing mechanism through the depositing port.

In an injection molding method, using a heating cylinder having on the front end thereof a discharge nozzle, a single axis screw is rotatable inside the heating cylinder, a fiber-supplying device fills reinforcing fiber into the heating cylinder, and injection molding is performed while supplying the reinforcing fiber and the resin starting material separately and supplying the reinforcing fiber on the front side of the resin starting material. The method includes a plasticization process for obtaining a specified amount of a kneaded product by retracting the screw while rotating in the normal direction to melt the resin starting material and knead reinforcing fiber into the melted resin starting material, and an injection process for discharging the kneaded product from the discharge nozzle by advancing the screw. Reinforcing fiber is supplied into the heating cylinder in the injection process.

A control device for an injection molding machine is equipped with a pressure acquisition unit that acquires a pressure of a resin inside a cylinder, a reverse rotation control unit that causes a screw to be rotated in reverse based on a predetermined reverse rotation condition so as to reduce the resin pressure after having moved the screw rearward to a metering position, a compensation amount calculation unit that calculates a compensation amount to be made with respect to the reverse rotation condition, based on the resin pressure inside the cylinder acquired by the pressure acquisition unit when the reverse rotation of the screw is stopped, and a predetermined compensation function, and a compensation processing unit configured to compensate the reverse rotation condition based on the compensation amount calculated by the compensation amount calculation unit.

A method is described for producing fibre-reinforced plastic moulded parts, wherein endless fibre strands are fed by a fibre braking device and/or cut fibres via a gravimetric metering device, and a plastic material to be melted, by a volumetric metering device are fed to a single-screw plasticizing unit. Plastic material which is molten and is mixed with fibre material is injected into a moulding tool by an injection stroke of the plasticizing screw. According to the application, the ACTUAL mass flow of the plastic material is calculated from the ACTUAL volume flow of the plastic material and from the ACTUAL mass flow of the fibre material. The ACTUAL mass flow of the plastic material is compared to a TARGET mass flow of the plastic material, and the rotation speed n.sub.d of the rotary drive of the metering element of the metering device is adapted.

A plasticizing device includes a flat screw including a groove forming surface in which a groove is formed, a barrel having a facing surface and a communication hole formed in the facing surface, the communication hole allowing a plasticized material to flow out, a heating unit, a flow path through which the plasticized material flows, a nozzle communicating with the flow path, a plurality of measurement units configured to measure pressures or temperatures in the flow path, an aspiration delivery unit, including a cylinder, having a branch flow path and a plunger configured to move in the cylinder so as to aspirate the plasticized material into the branch flow path or deliver the aspirated plasticized material to the nozzle, and a control unit configured to identify a state of the plasticized material in the flow path based on measurement values of the measurement units.

A molding system includes a molding machine, a mold disposed on the molding machine, a processing module, and a controller operably communicating with the processing module. The molding machine includes a barrel, a screw moving within the barrel, a driving motor driving the screw to move a molding material. The mold has a mold cavity with a die swell structure for being filled with the molding material. The processing module simulating a filling process of the molding material based on a molding condition including a predetermined screw speed for the molding machine, wherein simulating the filling process of the molding material comprises simulating a die swell effect of the molding material in the die swell structure by taking into consideration of an effective factor, a shear viscosity, an extension viscosity, a shear rate, and a molecular orientation effect of the molding material.